Improvement in hot-air furnaces



'1. FRIDLEY, up

Hot-Air Furnaces.

NO. 135,422. Patented Feb.4,1873.

AM P/mm-umnsRAPn/c ca me (vegan/v51; macaw) w JACOB FRIDLEY, JR, OF CARLISLE, PENNSYLVANIA.

IMPROVEMENT IN HOT-AIR FURNACES.

Specification forming part of Letters Patent No. 135,422, dated February 4, 1873.

To all whom it may con-corn:

Be it known that I, JACOB FRIDLEY, Jr., of Carlisle, in the county of Cumberland and State of Pennsylvania, have invented certain Improvements in Hot-Air Furnaces, of which the following is a specification:

The nature and objects of my invention consist in the construction of a heating-furnace that is simple in form, easily put together, and all parts being accessible and presenting a large surface of heated metal to the air that is being heated.

Figure 1 is'a perspective view of my furnace, with the outer shell G cut away to show the internal structure. Fig. 2 is a horizontal transverse section, showing those parts of the furnace which are cut by the line as as drawn across Fig. 1, and dividing the draft-hole E in two equal parts.

Ais the firepot, which is made, in the usual manner, of cast-iron or tire-clay. B B B, &c., are a series of cylindric tubes, made of wrought or cast iron, and inserted air-tight in the bottom plate Q and the top plate P, having the top and bottom open for the circulation of air. 0 O G G is an air-chamber in the form of a horseshoe, also open at the upper and lower parts. The inner shell D D forms the cylinder or fire-place, and it is pierced by the directdraft hole E, which is provided with a damper, F. G G is the outer shell of the furnace or radiator, and is cylindric in form, having an opening for the feeding-mouth of the furnace, which is not shown in the drawing, and the secondary draft-hole I at the back part, shown in Fig. 2. H II is the casing inclosing the furnace and confining the hot air, which is transmitted wherever it is wanted by the exit-tubes v m m. J is the ash-pit, It the base, 0 a support, and N N N N the feet of the furnace. K is an opening for the insertion of a reservoir or magazine when desired, which is always kept closed witha cap. M is the damper-rod which, through proper connections from the outside, regulates the damper F.

The fire is kindled in the pot A, keeping the damper F open until it is in a fair state of coin bustion, when the damper is closed and the combustible gases are reverberated and forced to circulate through the radiator occupied by the tubes B B B, &c., and impinging on said tubes in their passage and completely heating and heating-surfaces extend from the top to the bottom of the furnace as low down as the lower part of the fire-pot, and in this manner utilizing all the heat; and the hot gases do not merely ascend and find an exit at' the top like in other hot-air furnaces, but are obliged to revert and circulate horizontally before they are sufiered to escape. By this means a vast extent of metallic surface is heated and presented to the in-rushin g air to be heated.

The cold air comes in below the base R and enters the tubes B B B, 850., and the hollow chamber 0 (l at their lower parts, and also circulates around the entire furnace, and is con ducted through the building by opening exittubes at m.

I prefer the circular form for my furnace, as described above, but I do not confine myself to this shape, as it may be made elliptical, square, or polygonal, and be nearly or equally effective as a heating apparatus.

I claim as my invention- 1. In a hot-air furnace, a series of simple hot-air tubes, B B, 820., in combination with a radiator through which the products of combustion circulate, passing around such airtubes, substantially as described.

2. The combination of a tubular radiator, through which the products of combustion circulate, and cylinder D D, inclosin g a fire-place, A, and a hot-air chamber, (J 0, between said radiator and cylinder, substantially as and for the purpose set forth.

JACOB FRIDLEY, JR.

Witnesses:

O. L. LOGHMAN, EDGAR L. SHRYOOK. 

